Crop Protection Products for Organic Agriculture - ACS Publications

Chapter 7

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A Reduced Risk Insecticide for Organic Agriculture: Spinosad Case Study K e n n e t h D. R a c k e Dow AgroSciences, 9330 Zionsville Road, Indianapolis, I N 46268

Spinosad is a naturally-derived, insecticide generated during fermentation by the actinomycete bacteria Saccharopolyspora spinosa. Spinosad was approved for use in the U.S. on cotton and turfgrass during 1997 as part of E P A ' s reduced risk pesticide program based on its low mammalian toxicity, low environmental impacts, and compatibility with integrated pest management. As of 2005, spinosad has been approved for use on more than 150 fruit and vegetable crops in the U.S. and also in more than 70 other countries. Due to its unique, natural products origin and fermentation-based manufacturing, spinosad has been approved for use in certified organic agriculture in the U.S. by the U S D A National Organic Standards Board. Use of spinosad products in organic agriculture has also been authorized by other government and private certifying bodies in the U.S. including the Organic Materials Review Institute, and by similar organizations in other countries including Argentina, Australia, Guatemala, New Zealand, Peru, and Switzerland. This chapter provides a review of spinosad development, registration, and manufacturing efforts with particular attention to the approval and use of spinosad products in organic agriculture.

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© 2007 American Chemical Society In Crop Protection Products for Organic Agriculture; Felsot, A., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2006.

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Agrochemical discovery efforts are grueling and exhaustive searches for the proverbial "needle in a haystack". For every product that enters development, more than 100,000 candidate compounds and analogues will have been screened at one level or another (/). The discovery, characterization, and development phases are collectively both costly and time-consuming. It takes on average approximately 9 years to move from an exciting discovery in the laboratory to commercialization and an average investment of more than $150 million (/).

Discovery and Characterization Dow AgroSciences (formerly DowElanco) was formed during the 1980's as a joint venture of the Dow Chemical Company and Eli Lilly and Company (Dow later assumed full ownership), and both organizations brought a strong emphasis on evaluation of natural products as well as synthetic ones as potential pesticidal products. Thus, Dow AgroSciences interest has included evaluation of fermentation broths of soil microorganisms, live microorganisms, plant extracts, marine organism extracts, and insect toxins. Screening efforts during the mid-1980's identified insecticidal activity in a fermentation broth isolated from a soil sample collected several years earlier (Table I). A n initial screen demonstrated activity in a mosquito larval assay (Aedes aegpyti), and this activity was confirmed in a subsequent larval Lepidoptera assay (Spodoptera eridania) (2). Soon thereafter, the insecticidal activity was attributed to natural fermentation metabolites generated by a newly discovery soil bacterium (Order Actinomycetales, fungus-like bacteria), which was named Saccharopolyspora spinosa (3). The natural metabolites responsible for the insecticidal activity were termed "spinosyns". Subsequent work determined the chemical structure of the spinosyns as a suite of structurally related macrolides (4). The spinosyn molecule is built around a unique tetracyclic ring system to which two different sugars are attached. The most prominent and active of these compounds were spinosyn A and spinosyn D, and collectively these have been designated as the active ingredient "spinosad" (Fig 1). Spinosad active ingredient typically contains spinosyns A and D in roughly a 5:1 to 6:1 ratio. Additional efficacy testing revealed that spinosad demonstrated excellent insecticidal activity against a broad spectrum of pest Lepidoptera and Thysanoptera. In addition, spinosad was found to be highly active against other insects including selected Diptera, Coleoptera, Orthoptera, Siphonaptera, and Anoplura (5). Spinosad was also determined to have a unique mode of insecticidal action, distinct from all other known insecticides (6).

In Crop Protection Products for Organic Agriculture; Felsot, A., et al.; ACS Symposium Series; American Chemical Society: Washington, DC, 2006.

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R


spinosyn A: spinosyn D:

R=H MW = 732 R = CH3 MW = 746

Figure L Chemical Structure of Spinosad

Table I. Milestones in Spinosad Discovery, Development and Registration Date 1982 1985

1985

1988 1989 1991 1994 1995 1996 1997 1999 1999-2001 2002 2003

Milestone Soil sample collected from rum distillery in the Virgin Islands Screening of fermentation broth from soil sample demonstrates biological activity toward mosquito and southern armyworm larvae Newly discovered bacterium isolated from fermentation broth, Saccharopolyspora spinosa, found to produce active substances named "spinosyns" First field efficacy trials initiated Structure of spinosyn A determined Predevelopment regulatory research program initiated Product commercialization and development program initiated Submission of full registration data package to U.S. E P A and other regulatory authorities First global registration approval of spinosad in Korea First U.S. registration approval for cotton, turfgrass and ornamentals Spinosad recognized with Presidential Green Chemistry Challenge Award for "designing safer chemicals" First organic agriculture approvals by bodies in Switzerland, Tunisia, and U.S. U S D A National Organic Standards Board approval of spinosad for use in certified organic agriculture First set of Codex maximum residue limits (MRL's) established for spinosad following W H O and F A Q evaluations


95


Development and Registration Testing Following characterization of the insecticidal activity of spinosad, a key decision regarding pursuit of a commercial development program had to be reached. Given the time and cost involved in the development and registration process, the decision to proceed with a candidate such as spinosad was a significant one. Early biological efficacy and safety testing identified spinosad as a highly efficacious and low human/environmental impact compound. The decision to proceed forward with testing that would lead to commercialization was reached during 1990. In light of the extremely high activity shown by spinosad against key pest Lepidoptera, initial development efforts were focused on agricultural use on cotton and non-agricultural use on turfgrass and ornamental plants. Biological testing efforts were quickly focused on two different soluble concentrate (SC) formulations, Tracer* (44.2% active ingredient) for agricultural use and Conserve* (11.6% active ingredient) for non-agricultural use (*Trademark of Dow AgroSciences). Small-plot field research trials on cotton through 1994 were focused on the Heliothine pests and beet armyworm (Spodoptera exigua), with research conducted in the U.S. as well as Australia, Brazil, Colombia, Egypt, Greece, India, and Pakistan. Beginning in 1995, large-plot (-10 acres) cotton field trials were initiated in the U.S. through an extensive experimental use permit (EUP) program (7). A comparable turf and ornamental field E U P program was initiated in the U.S. during 1996, and it was focused on pest cutworms (e.g., Agrotis ipsilon), armyworms (e.g., Spodoptera frugiperda), and webworms (Parapediasia teterella) (8). Promising results from both programs confirmed the effectiveness of spinosad at low use rates ranging from 0.0450.123 kg/ha (0.04 to 0.11 lb ai/acre) (7,8). A n intensive predevelopment registration testing program of chemistry, toxicology, and environmental studies was initiated for spinosad during 1991. In addition to laboratory studies with various test organisms and systems, field studies to characterize the behavior of spinosad residues in soil, water, and on plants were also conducted. Following completion of the core registration data package during 1995, it became clear that spinosad possessed an extremely favorable combination of properties from a registration standpoint with respect to both human and environmental safety considerations (Table II). Thus, it qualified for a reduced risk classification and accelerated regulatory evaluation at U.S. E P A based on its lower mammalian toxicity, lower environmental impacts, and greater compatibility with I P M programs as compared with available alternatives (9). It is important to emphasize the significant database of Dow AgroSciences and independent testing information that undergirds the efficacious use of spinosad. In addition to the core registration and efficacy testing data required for evaluation by government authorities and universities, researchers have


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Table II. Key Regulatory Properties of Spinosad Reduced Risk Criteria Low mammalian toxicity

Properties Rat (oral) LD50 >5000 (F) and >3738 mg/kg (M) Rabbit (dermal) LD50 >2000 mg/kg Very slight dermal and ocular irritant Not a skin sensitizer Not mutagenic or carcinogenic

Low environmental impacts

Soil half-life = 9 - 1 7 days Soil sorption Kd = 5 - 323 (low mobility) Daphnid LC50 = 14 mg/L; Trout = 30 mg/L Quail LD50> 1333 mg/kg

Compatibility with IPM

Low toxicity to beneficial predators/parasitoids Unique mode of insecticidal action

Sources: (9,10)

actively communicated this storehouse of information on spinosad in the peerreviewed scientific literature. Key publications for spinosad are available concerning its discovery and characterization (2-5), biological efficacy (11,12), residue chemistry and analysis (75-75), mammalian toxicology (16-19), environmental fate and impacts (20-22), and safety to beneficial insects and arthropods (23,24).

Registration History The distinction for the first registration approval for spinosad goes to South Korea, which approved use of the product on vegetables during 1996. The U.S. registration for use of spinosad on cotton as well on turf and ornamentals occurred during February, 1997. Spinosad was the first food-use new active ingredient approved by E P A following implementation of the Food Quality Protection Act, which imposed stringent new evaluation criteria concerning human exposure and risk assessment. U.S. approvals for fruiting vegetables, brassica vegetables, leafy vegetables, apples, and citrus followed during April, 1998. Since that time, there have been a significant number of label expansions for a large number of fruit, vegetable, and nut crops, and as of 2004 spinosad has been approved for use on more than 150 crops. A critical partner in the rapid label expansion of spinosad uses has been the U S D A IR-4 (Interregional Research Project No. 4) Center for Minor Crop Pest Management. The IR-4 program has been responsible for collaborating on obtaining data and petitioning



97 E P A in support of a large number of minor crops ranging from asparagus to cranberry to mint. U S D A has also been an important partner in the current expansion of spinosad use for stored grain pest control, for which registration approval was granted during 2005. In addition to crop uses, spinosad has also been approved by U.S. E P A for fire ant control and for housefly control in and around livestock facilities, both uses that involve bait formulations. Through a partnership with E l i Lilly and Company, spinosad has also been developed for animal health uses, and U.S. approval for an external cattle spray/pour-on product to control ectoparasites occurred during 2002. Although most spinosad registrations around the world have involved traditional SC formulations or, in a few instances granular bait products (Table HI), the GF-120 fruit fly bait has been a unique offering approved in the U.S. during 2002. This dilute (0.02% a.i.) liquid bait product was developed jointly by Dow AgroSciences and the U S D A - A R S Fruit Quality and Fruit Insects Research Unit under a cooperative research and development agreement. Plant proteins and sugars that are highly attractive and phagostimulating to many tephritid fruit fly species comprise the bulk of the bait. After dilution, GF-120 is typically applied to susceptible fruit crops such as citrus, apples, pears, peaches, and olives as well as other crops and non-crop vegetation to control fruit fly outbreaks aerially by U L V spray or by targeted ground sprays at very low use rates of 0.0019-0.00038 kg ai/ha (0.00017-0.00034 lb ai/acre). In the U.S., E P A has granted a blanket tolerance of 0.02 ppm on all raw agricultural commodities to allow the widespread use of this bait product. This fruit fly bait has been an important tool in combating fruit fly infestations, often on an emergency basis, in California, Florida, and Central America. Spinosad also received one the nation's top environmental honors, the Presidential Green Chemistry Challenge Award, during 1999. This award recognized technologies that incorporate the principles of green chemistry into chemical design, manufacture, and use, and spinosad was honored as a new, natural product for insect control with environmentally compatible characteristics. On an international basis, as of 2004 spinosad had been approved for use in more than 70 countries including Australia, Brazil, Canada, Italy, Japan, Mexico, and U K . Addition of spinosad to the EU-wide Annex I listing of approved active ingredients was also nearing finalization. Spinosad has been classified by the W H O (World Health Organization) International Programme on Chemical Safety as a product "unlikely to present acute hazard", which represents the most favorable of 5 classifications recognized by this advisory body. The F A O / W H O Joint Meeting on Pesticide Residues (JMPR) completed a comprehensive evaluation of spinosad toxicology, plant and animal metabolism, and residue chemistry during 2001, and based on the positive outcome MRL's to support international trade were promulgated by the Codex


98 Table III. Spinosad Formulated Products Type

SC SC

Active Ingredient Cone (w/w) 44.2% 22.8%

Primary Uses

Trade Names

Agriculture

b

Tracer Audienz Success Spintor

b

Agriculture

b


b

Agriculture Turf and ornamental

SC

11.6%

Conserve

SC

0.5%

Spinosad 0.5% SC

WP

80.0%

Entrust

SC

0.02%

GF-120 Fruit Fly Bait Success 0.02 C B

b

Home and garden U.S. Organic: List 4 inerts Agriculture U.S. Organic: List 4 inerts

5

Fruit fly baiting U.S. Organic: List 4 inerts

b

b

GR GR

0.015% 1%

b

Justice Fire Ant Bait Conserve Fire Ant Bait Biospin Iprasan

b

b

Fire ant baiting U.S. Organic: List 4 inerts Housefly baiting

b

EC

2.5%

Extinosad

0

External livestock pour-on and spray

a

SC = suspension concentrate, WP = wettable powder, GR = granular, EC = emulsifiable concentrate b

Trademark of Dow AgroSciences

Trademark of Eli Lilly and Company

Alimentarius Commission during 2003. The W H O Pesticide Evaluation Scheme (WHOPES) was also currently evaluating spinosad as a future candidate for mosquito larvae control.

Fermentation Source As a basic producer of crop protection chemicals, Dow AgroSciences has a strong history of chemical synthesis and manufacturing. In conjunction with the manufacturing of spinosad, a world-class capability in fermentation technology has also been developed. The natural fermentation origins of spinosad have


99 been continued in commercial manufacturing. Unlike some other product classes for which natural origins later gave rise to synthetic analogues (e.g., natural pyrethrins from Chrysanthemum as the forerunners of synthetic pyrethroids), commercial production of spinosad today still involves the labors of the same, humble soil bacterium first isolated in the early 1980's.


Microbiology Saccharopolyspora spinosa is the soil bacterium that during 1985 was discovered to produce spinosad (3). The sample from which this microorganism was first isolated was collected from soil inside a defunct sugar mill rum still in the Virgin Islands. S. spinosa is a gram-positive, non-motile, spore-forming, filamentous bacterium or actinomycete. The Genus Saccharopolyspora was previously established based on the type species S. hirsute, which was isolated from sugarcane bagasse. The assignment of the newly discovered, spinosadproducing bacterium to this Genus was based on a suite of observed cultural, morphological, and physiological characteristics; the species name spinosa was based on the very distinctive spiny exterior surface of the bacterial cells observed under microscopic magnification. This species name also formed the basis for the nomenclature of spinosad and the spinosyns. During growth and aerobic fermentation activity, S. spinosa produces as secondary metabolites the spinosyns that comprise spinosad. The proposed biosynthetic pathway involved is thought to comprise three primary series of steps. First, the core macrolide structure appears to be formed by successive addition of nine acetate and two proprionate units. Second, the rhamnose sugar unit is formed and bound to the macrolide core. Third, the forosamine sugar unit is synthesized and bound to the macrolide core. The genetic basis for the biosynthesis has also been investigated (25). The fermentation culture conditions under which S. spinosa produces spinosad requires aeration to maintain oxygenated conditions. A favorable aqueous growth medium contains proteins, carbohydrates, oils, and minerals (e.g., corn solids, cottonseed flour, soybean flour, glucose, methyl oleate, calcium carbonate) (26).

Manufacturing Fermentation manufacturing of spinosad occurs at the Dow AgroSciences facility located in Harbor Beach, Michigan using patented processes (26). Effective deployment of the spinosyn synthetic pathway is the responsibility of S. spinosa, and the role of this state-of-the-art fermentation facility is to create the correct conditions under which this fascinating microbe can do its duty.


100 Inoculum Development Ψ Fermentation Ψ


Broth Extraction Ψ Solvent Exchange and Protonation Ψ Precipitation Figure 2. Spinosad Manufacturing Steps

There are 5 major steps involved in the fermentation manufacturing of spinosad (Figure 2). First, an inoculum of S. spinosa is developed at sufficient scale to serve as a seed for an upcoming fermentation run. Although strain development efforts on the part of Dow AgroSciences microbiologists have identified mutants for production with increased spinosad-producing capabilities, no genetic engineering techniques are employed in the strain improvement process and no genetically modified organisms are used for manufacturing. Second, a large-scale fermentation is completed. Each fermentation cycle begins with inoculation of a fresh batch of sterile growth medium. Vegetative inoculum is grown by a submerged aerobic fermentation process. The aqueous growth media contain proteins, carbohydrates, oils, and minerals. Corn solids, cottonseed flour, soybean flour, glucose, methyl oleate, and calcium carbonate may be part of the media. During the period of fermentation, spinosad accumulates in the fermentation broth. Third, at the end of the fermentation period the accumulated spinosad is extracted from the spent fermentation broth by a solvent such as methanol. The solvent solution is centrifiiged or filtered to remove solids and then is concentrated by distillation. Fourth, spinosad present in the concentrated extraction solvent is backextracted into an acidified aqueous solution.


101 Fifth, the spinosad in the aqueous solution is precipitated following base neutralization. Crystals of spinosad are then de-watered and dried for use in formulated products. The technical spinosad product typically contains about 90% spinosyns and 10% impurities from the growth medium.


Certified Organic Approvals

Early Experiences In light of the natural fermentation origin of spinosad and its basic nature as a biopesticide, interest arose early on the part of growers with respect to the use of spinosad in organic agriculture. From a commercial standpoint, the first limited launch of spinosad for cotton occurred during 1997, and fiill launch on cotton and other crops occurred during 1998. In the U.S., the first recognition of the potential utility of spinosad for organic agriculture came at the state level. For example, the Colorado Department of Agriculture added SpinTor SC to its listing of approved pesticides for use on certified organic farms during 1999. Similarly, the Texas Department of Agriculture authorized temporary approval for use of Tracer SC in organic cotton. Outside the U.S., local listings for use of spinosad products were recognized in Switzerland by F I B L (Audienz), in Tunisia by the Ministry of Agriculture (Tracer), and in Austria by AustriaBioGarantie (Iprasan). In most cases these authorizations or recommendations resulted from local, grassroots requests on the part of growers to the organic listing/certifying body. Early experiences with other organic listing/certification bodies, however, raised some questions and concerns about the ease with which spinosad would be adopted for use in organic agriculture. Basic concerns also surfaced concerning the inherent nature of the divergent organic product evaluation and approval processes employed. For example, during 1988 the Organic Materials Review Institute (OMRI) of Eugene, Oregon, an influential certification body in the U.S. and overseas, determined that the active ingredient spinosad was determined to be non-synthetic and therefore allowed for organic production. However, O M R I did not agree to list the formulated spinosad-containing product under consideration, Success SC, because one or more coformulants/inerts were "unresolved" as to their organic suitability. Likewise, the Bio-Dynamic Institute (IBD) in Brazil rejected use of Tracer SC for organic agriculture due, not to the active ingredient composition, but rather the nonactive ingredient, co-formulant content. How could spinosad be acceptable for organic growers in Colorado and Texas and Switzerland, but not for organic growers in Brazil or those in the U.S. with allegiance to OMRI? Since the


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mixed experience of spinosad with certifying/listing bodies occurred also at a time when available market research was showing a rapidly expanding but rather uncertain commercial value, some réévaluation and redirection in organic certification efforts for spinosad was in order. However, some harmonization of organic recognition processes also appeared necessary for further progress especially in the U.S., since it had become all too apparent that rather than a unified, monolithic organic certification/listing process what instead existed was a crazy-quilt of government and private, local and national authorizing bodies with disparate criteria and definitions.

U.S. Organic Agriculture A couple of major developments during the late 1990's paved the way for a much clearer definition of the approval process for organic agriculture inputs in the U.S. The first of these developments involved U S D A . Although the 1990 Organic Food Production Act (OFPA) established the basis for a national organic program, it wasn't until December, 2000 that final standards for operation of the U S D A National Organic Program (NOP) were promulgated (27). Thus, a well-defined evaluation process for creating a single, nationally recognized list of approved substances for use in organic agriculture was created. In addition, U S D A established criteria with respect to co-formulants, by recognizing that any substance on the national list was suitable for organic agriculture only i f any co-formulants were classified by U.S. E P A as List 4 inert ingredients. The second development, then, involved U.S. E P A and product labeling criteria. During early 2003, U.S. E P A published its long-awaited policy with respect to labeling of pesticide products under the National Organic Program, which authorized the addition of the statement "For Organic Production" to the label of those products containing 1) active ingredients on the U S D A N O P National Listing and 2) containing only E P A List 4 inert ingredients (28). A petition to request evaluation of spinosad as a N O P listed active ingredient was submitted to the U S D A National Organic Standards Board (NOSB) during early 2002. In advance of the evaluation meeting, it is interesting to note that dozens of letters to support a positive listing of spinosad poured into U S D A on behalf of various state and federal programs, universities, crop consultants, grower organizations, and even foreign governments (especially Central America where the M O S C A M E D fruit fly eradication program was in operation). During May, 2002 the U S D A N O S B completed its evaluation of spinosad and determined that, due to its natural, fermentation source and relatively benign toxicological profile, spinosad was compatible with organic agriculture and allowed for use in organic agriculture. This was a major milestone, then, in the recognition of spinosad for U.S. organic agriculture.



103 With respect to formulations most appropriate for use in organic agriculture and containing only E P A List 4 inert ingredients, Dow AgroSciences narrowed its initial focus in the U.S. to 4 primary products (Table III). This was not an easy task since some commonly employed co-formulants (e.g., surfactants, emulsifiers, stabilizers), especially those for liquid formulations (e.g., SC, E C ) , are not on List 4 but rather appear on other E P A approved inert lists (e.g., List 3). The first product of focus was a wettable powder for agricultural use. Entrust 80 WP was a slightly modified version of a wettable granule that had been developed and registered earlier but had not been previously commercialized. The second product was an existing granular, corn-grit based bait intended for fire ant control first developed and registered during 1998 (Conserve, Justice). The third product was a liquid concentrate for dilution and spraying as a finit fly bait (GF-120), for which a slightly modified version (GF120NF) of a product first approved for emergency use during 2000 was developed. This slight modification involved removal of a synthetic preservative. Labels for these formulated products, containing only spinosad and List 4 inert ingredients, were approved by U.S. E P A during 2003 following promulgation of the E P A organic labeling policy. A more recently developed product is Spinosad 0.5% SC, which is available for home and garden use. Organic certifications and listings for spinosad products continue to occur in the U.S. by state agencies and private certifiers. For example, the Washington Department of Agriculture approved Entrust for use in organic food production during 2003. Also, the Organic Materials Review Institute (OMRI) evaluated spinosad formulated products and decided during early 2003 to approve the use of Entrust, GF-120NF, and Con verve Fire Ant Bait for organic agriculture (Table IV). Although the introduction and adoption of spinosad products in the U.S. for organic agriculture is still at an early stage, there have been some early successes. O f particular note was the utility of spinosad in addressing a crisis which developed in California during 2002, when a significant agricultural segment of the state was threatened by infestation of the Mexican Fruit Fly. The California Department of Food and Agriculture (CDFA) approved the emergency use of GF-120 N F within a 28-mile quarantine section of San Diego County on crops including grapefruit and avocado. Since there were a significant number of organic growers present in the quarantine zone, the organic certification status of spinosad and the GF-120 N F product was a critical component to the success of this program.

International Organic Agriculture Outside the U.S., there are a variety of government and private certifiers of organic agriculture and allowable inputs, including pesticides, and there may be


104


Table IV. Examples of Spinosad Organic Approvals Produces)

Country Argentina

Certifying Body Senesa Organics

Entrust

Australia

Australia Certified Organic Pty Ltd

Entrust 80W Naturalyte Fruit Fly Bait

Guatemala

Mayacert B C S Oko-Garantie

GF-120NF

New Zealand

Bio-Grow

Entrust 80W

Peru

Senasa

Success 0.02 C B

Spain

Sociedad Espanola de Agricultura Ecologica (SEAE)

SpinTor 48

Switzerland

Forschungsinstitut fur biologischen Landau (FIBL)

Audienz SC

Tunisia

Ministry of Agriculture

Tracer SC

U.S.

U S D A National Organic Standards Board

Technical Spinosad

U.S.

U.S. E P A Office of Pesticide Programs

GF-120 N F Entrust 80W Conserve Fire Ant Bait Spinosad 0.5% SC

U.S.

Colorado Department of Agriculture

SpinTor

U.S.

Washington State Department of Agriculture

Entrust GF-120 N F

U.S.

Organic Materials Review Institute (OMRI)

GF-120 N F Entrust 80W Conserve Fire Ant Bait Spinosad 0.5% SC

SpinTor C E B O (GF-120)

a single body or multiple approval/listing bodies within each country. Although growers in some countries reference certifying agencies or bodies in their own countries, in other cases growers or grower organizations reference and/or are certified by foreign groups. In fact, it is common for growers in agricultural exporting countries to be required to have certification by bodies in the countries to which they ship their organic produce. For example, organic coffee growers



105 in Central America export mostly to the U.S. and Europe, so reference to the U S D A N O P listing of approved products or certification by authorizing bodies in some European countries (e.g., B C S Oko-Garantie in Germany) may be required. Similarly, organic fruit or flower growers in Africa may need to secure certification and use only pesticides approved by such European bodies as Ecocert or M P S in order to ship organic products to Germany or the Netherlands, respectively. Spinosad products have been approved/listed for use in organic agriculture by a number of organizations outside the U.S. (Table IV). Early approvals came in Switzerland and Tunisia. More recent approvals during 2003 have come for specific products in Argentina, Australia, Guatemala, New Zealand, and Peru. In some countries (e.g., Australia, New Zealand) the specific formulations developed and approved for use in the U.S., particularly Entrust and GF-120NF, have been the products also compatible with national organic product requirements. In other countries, organic product requirements are primarily focused on the active ingredient rather than the co-formulants. For example, in the European Union, a great degree of scrutiny is placed on products of microbial origin to ensure that no involvement of genetically modified organisms or their byproducts are utilized. As far as international standards for organic agriculture, the Codex Alimentarius Commission has developed guidelines for the production, processing, labeling, and marketing of organically produced foods (29). Ongoing activities through the Joint F A O / W H O Food Standards Program and the Codex Committee on Food Labeling continue to grapple with considerations related to development of an international listing of pesticide products suitable for use in organic agriculture, but competing national priorities and agendas have thus far interfered with significant progress at the international level. The greatest single success for spinosad with respect to organic agriculture outside the U.S. has been associated with the M O S C A M E D program in Central America (30). This cooperative program of the U.S. Department of Agriculture's Animal and Plant Health Inspection Service (APHIS) and the governments of Mexico and Guatemala is targeted at preventing the invasion of North and Central America by the Mediterranean Fruit Fly or Medfly. So far, control efforts have focused on creation of a Medfly-free zone across the Central American isthmus and have included area-wide application of pest suppression practices. The spinosad fruit fly bait GF-120NF has been a primary tool of the M O S C A M E D program due to both its highly efficacious nature and favorable environmental profile when considered for area-wide, low-volume spraying. In addition, the organic certification of spinosad by U S D A and of GF-120NF by regional organic certifiers such as Mayacert, have enabled the use of the product across a regional landscape shared by both conventional and organic growers.


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Benefits and Future Considerations The recognition of spinosad as suitable for use in certified organic agriculture has made a highly efficacious product with a highly favorable regulatory profile available to organic growers both in the U.S. and around the world. In addition to individual grower benefits, spinosad has also proven to be a critical component of area-wide control programs (e.g., Medfly) from an efficacy and public acceptability standpoint, most particularly when the area of infestation has included both conventional and organic farms and orchards. For management of the pests for which spinosad is effective, there is no longer a need for growers with organic interests or inclinations to choose between certified products of often dubious performance and effective products of synthetic chemical origin. Involvement in organic certification efforts for spinosad has also been a key learning experience for a basic agricultural chemical producer such as Dow AgroSciences with respect to the needs and requirements of organic agriculture. This experience has included exposure to both the positive aspects and foibles of the organic movement. Particularly eye-opening has been the extremely high focus on origin and composition of pest management products which organic growers are willing to employ, with human and environmental safety factors important but clearly secondary considerations. For example, the basic tenets of organic agriculture would seem often to favor naturally-derived products which may in some cases lack the comprehensive safety testing (e.g., chronic mammalian toxicity, environmental chemistry, residue chemistry) and risk assessments required for synthetic chemicals. Hopefully, spinosad will be only one of a number of modern and well-tested products of natural origin available to the organic grower. Future Dow AgroSciences efforts may be focused on both expansion of uses for existing organic formulations and development of additional organic formulations for various organic agriculture market segments. For example, U.S. approval of spinosad for stored grain use included submission of both conventional SC and organic (Entrust 80W) formulations. In addition, efforts at obtaining recognition of spinosad's utility in organic agriculture in other countries will be continued. Most notably this will include additional efforts in E U member states following the Annex I listing of spinosad as an approved active substance. Finally, interest in advancement of other products for use in organic agriculture will also be continued.

References 1.

Anonymous. The Cost of New Agrochemical Product Discovery, Development and Registration in 1995 and 2000. Phillips-McDougall. Midlothian, U K . April, 2003.


107 2. 3. 4.


5.

6. 7. 8. 9.

10. 11. 12.

13. 14. 15.

16. 17. 18. 19.

Thompson, G . D.; Dutton, R.; Sparks, T. C. Pest. Manag. Sci. 2000, 56, 696-702. Mertz, F. P.; Yao, R. C. Int. J. System. Bacteriol. 1990, 40, 34-39. Kirst, H . Α.; Michel, K . H . ; Mynderse, J. S.; Creemer, L . C.; Chio, E . H . ; Yao, R. C.; Nakatsukasa, W. M.; Boeck, L . D.; Occolowitz, J. L . ; Paschal, J. W.; Deeter, J. B . ; Jones, N. D.; Thompson, G. D. Tetrahedron Lett. 1991, 32, 4839-4842. DeAmicis, C. V . ; Dripps, J. E.; Hatton, C. J.; Karr, L . L . In: Phytochemicals for Pest Control. Hedin, P. Α.; Hollingworth, R. M.; Masler, E. P.; Miyamoto, J.; Thompson, D . G., Eds. Symposium Series 658, American Chemical Society, Washington, D C , 1997, pp 144-154. Salgado, V . L . Pestic. Biochem. Physiol. 1998, 60, 91-102. Nolting, S. P.; Huckaba, R. M.; Nead, Β. Α.; Peterson, L . G.; Porteous, D . J.; Borth, P. W. Down to Earth, 1997, 52, 21-27. Breuninger, J. M.; Keese, R. J.; Jentes, C. E.; Handley, J. V . ; Cooper, R. B.; Tolley, M. P. Down to Earth, 1998, 53, 1-5. LaRocca, G . Pesticide Fact Sheet: Spinosad. U.S. Environmental Protection Agency, Office of Pesticide Programs, Washington, D C , February, 1997. Anonymous. Spinosad Technical Bulletin. Dow AgroSciences, Indianapolis, IN, 2001. Sparks, T. C.; Thompson, G . D.; Kirst, H . Α.; Hertlein, M. B.; Larson, L. L.; Worden, T. V . ; Thibault, S. T. J. Econ. Entomol. 1998, 91, 1277-1283. Crouse Crouse, G . D.; Sparks, T. C.; DeAmicis, C. V . ; Kirst, H . Α.; Martynow, J. G.; Creemer, L . C.; Worden, T. V . ; Anzeveno, P. B . In: Pesticide Chemistry and Bioscience: The Food-Environment Challenge. Brooks, G . T.; Roberts, T. R., Eds., Royal Society of Chemistry, London, U K , 1999, pp 155-166. West, S.D.; Yeh, L.T.; Turner, L . G . ; Schwedler, D . A . ; Thomas, A . D . ; Dubelbeis, D.O. J. Agric. Food Chem. 2000, 48, 5131-5137. Schwedler, D . Α.; Thomas, A . D.; Yeh, L. T. J. Agric. Food Chem. 2000, 48, 5138-5145. Young, D . L . ; Mihaliak, C. Α.; West, S. D.; Hanselman, Κ. Α.; Collins, R. Α.; Phillips, A . M.; Robb, C. K . J. Agric. Food Chem. 2000, 48, 51465153. Yano, B . L . ; Bond, D . M . ; Novilla, M . N . ; McFadden, L . G . ; Reasor, M . J . Toxicol. Sci. 2002, 65, 288-298. Stebbins, K . E . ; Bond, D . M . ; Novilla, M . N . ; Reasor, M . J . Toxicol. Sci. 2002, 65, 276-287. Hanley, T.R.; Breslin, W.J.; Quast, J.F.; Carney, E.W. Toxicol. Sci. 2002, 67, 144-152. Breslin, W. J.; Marty, M. S.; Vedula, U. V . ; Liberacki, A . B . ; Yano, B . L. Food Chem. Toxicol. 2000, 38, 1103-1112.



108 20. Hale, Κ. Α.; Portwood, D. E . J. Environ. Sci. Health, 1996, B31, 477-484. 21. Cleveland, C.B.; Bormett, G.A.; Saunders, D.G.; Powers, F.L.; McGibbon, A.S.; Reeves, G . L . ; Rutherford, L . ; Balcer, J.L. J. Agric. Food Chem. 2002, 50, 3244-3256. 22. Cleveland, C.B.; Mayes, M . A . ; Oyer, S.A. Pest Manage. Sci. 2001, 58, 7084. 23. Williams, T.; Valle, J.; Vinuela, E . Biocontrol Sci. Technol. 2003, 13, 459-475. 24. Mayes, M . A . ; Thompson, G . ; Husband, B . ; Miles, M . M . Rev. Environ. Contam. Toxicol. 2003, 179, 37-71. 25. Madduri, K . ; Waldron, C.; Matsushima, P.; Broughton, M . C . ; Crawford, K . ; Merlo, D.J.; Baltz, R . H . J. Industr. Microbiol. Biotechnol. 2001, 27, 399402. 26. Boeck, L . D.; Chio, H . ; Eaton, T. E . ; Godfrey, Ο. W.; Michel, K . H . ; Nakatsukasa, W . M.; Yao, R. C. U.S. Patent 5, 571, 901, 1996. 27. U.S. Code of Federal Regulations, 7 C F R Part 205, 2000. 28. Mulkey, M. E . Labeling of Pesticide Products under the National Organic Program. U . S . Environmental Protection Agency, Office of Pesticide Programs, Pesticide Registration Notice 2003-1, E P A 730-N-03-001, 2003. 29. Anonymous. Guidelines for the Production, Processing, Labelling and Marketing of Organically Produced Foods. Codex Alimentarius Commission, Codex Committee on Food Labelling, Joint F A O / W H O Food Standards Programme, G L 32-1999, Rev. 1, Rome, Italy, 2001. 30. Tween, G . Spinosad for the Moscamed Program: Environmental Analysis. U.S. Department o f Agriculture, Animal and Plant Health Inspection Service, Washington, D C , 2001.


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